生活垃圾焚烧炉积灰结渣问题研究

对生活垃圾焚烧锅炉积灰结渣的理化性质、形成过程、形成机理等进行了综述。其中机理主要从碱金属熔融、Ca-S体系积灰、固相烧结3种类型进行了详细介绍。对除渣的普遍方法进行了总结;对清灰除焦剂的发展提出了建议。     

生物质灰化学特性的研究

采用灰成分分析及X-ray衍射方法,对甘蔗渣、松木屑、花生壳及谷壳四种常见的生物质灰特性进行了研究。研究表明：在气化过程中,甘蔗渣和松木屑的积灰、结渣倾向严重,花生壳次之,谷壳相对轻微。对其灰中碱金属的固留研究,分析了甘蔗渣和松木屑的积灰、结渣倾向严重的原因。     

富磷添加剂对生物质燃烧中积灰结渣和腐蚀作用的探析

文章探讨了富磷添加剂对生物质燃烧过程中锅炉受热面积灰、结渣和腐蚀的作用机理,分析了其作用效果,考察了燃烧温度、燃烧气氛、生物质种类、Ca/K摩尔比、P/K摩尔比等主要因素对作用效果的影响规律。结果表明,富磷添加剂可以将烟气中的碱金属(主要是钾)和氯元素固定于底灰中,生成高熔点化合物,减轻碱金属熔融结渣和氯腐蚀。同时,添加剂改变了灰的物理和化学性质,使灰松软不易烧结,从而有效减轻了生物质燃烧过程中锅炉受热面的积灰、结渣和腐蚀。     

浮萍生物质灰分的特性分析

利用低温成灰的方法对两种浮萍(紫萍和青萍)进行灰化,测定灰分含量,通过SEM/EDS分析、X射线衍射分析和TGA/DSC分析实验对两种灰分的形貌、成分、热活动等进行对比研究。结果显示:浮萍灰分中碱金属、碱土金属和氯含量高,硅含量低。灰分中KCl含量大,在温度升高时挥发量大,灰分的积灰结渣倾向严重。对于两种浮萍而言,紫萍的积灰结渣倾向重于青萍。这些结果表明在浮萍生物质燃烧和气化利用中应重视碱金属挥发和熔化所带来的积灰结渣问题。     

燃气脉冲吹灰装置在焦结炉余热锅炉上的应用

介绍火法锌冶炼焦结炉余热锅炉的积灰部位，并分析积灰的成因。简述燃气脉冲吹灰装置的作用机理，总结了燃气脉冲吹灰装置在焦结炉余热锅炉上的应用效果。     

生物质燃烧过程中的积灰结渣特性

从燃料特性的角度来阐明生物质燃烧过程中的积灰结渣特性。简要地对生物质灰组分进行了分析,重点论述生物质在燃烧过程中的积灰结渣机理、影响积灰结渣的几种重要元素和评价积灰结渣特性的指标。     

空气预热器硫酸氢铵积灰的数值研究

建立了适用于液态黏性NH_4HSO_4沉积的积灰模型,对某SCR脱硝改造后的300MW机组回转式空气预热器蓄热板的积灰过程进行了数值模拟,分析了烟灰颗粒法向碰撞速度和角度、积灰强度、积灰厚度及积灰概率等积灰特性的变化规律.结果表明:在NH_4HSO_4沉积区,上、下板平均积灰强度分别为普通积灰区的7.3倍和4.5倍,且不同颗粒粒径的积灰概率保持在90%左右,而在普通积灰区均小于35%;上板平均积灰强度约为下板平均积灰强度的2倍;积灰厚度与积灰强度的分布规律一致.     

碱金属钠盐冷凝行为的实验研究

准东煤燃烧过程中,碱金属Na盐蒸气在锅炉对流受热面上的冷凝是形成积灰层的初始必要条件.利用一维沉降炉和冷凝采样器,对NaCl、Na2SO4及两者混合物的冷凝行为进行了实验研究.结果表明:NaCl、Na2SO4及两者混合物的冷凝温度分别为800 ℃、770℃和780?790 ℃.利用扫描电镜-X射线能谱(SEM-EDX)...     

钾对生物质燃烧过程积灰的影响

对生物中钾的赋存形式及其沉积过程进行分析得出钾含量高且反应性高是影响积灰形成的关键因素。研究了钾对飞灰特性的影响以及烟气中钾浓度对积灰的影响,研究结果表明,钾促进了积灰的形成。钾促进积灰形成的主要途径是:钾与硅酸盐结合形成低熔点化合物促进灰粒间的烧结;钾沉积在飞灰颗粒的表面增加了飞灰的表面粘性。最后介绍了几种减轻钾对积灰形成的影响的方法。     

生物质与煤矸石(煤系高岭土)共燃行为及固定碱金属特性研究

采用热重(TG)分析和电感耦合等离子体发射光谱仪(ICP-OES)研究了秸秆和煤矸石单独燃烧和共燃烧过程中的燃烧特性以及秸秆中碱金属元素的固留特性,采用Coats-Redfern积分法对秸秆和煤矸石共燃烧过程进行了动力学特性分析。结果表明：秸秆与煤矸石的混燃过程中存在强烈的交互作用,其中煤矸石掺混比例为10%时燃烧特性最优,混燃时随着煤矸石的添加,混合物的固定碳燃烧反应活化能降低且交互作用改变了燃烧过程中的反应机理;煤矸石质量分数为10%时对碱金属的释放抑制效果最好,在该比例下碱金属K、Na分别在1 000℃与1 100℃时的固定效果最优。     

城市垃圾焚烧产物对环境的影响及其资源化利用

阐述了城市垃圾焚烧飞灰的基本性质和不同粒径颗粒所含各种重金属含量以及它们对水体和环境的危害,介绍了不同粒径飞灰的物理化学性质和在不同条件下的处理方式,在此基础上提出了一种"无害化"、"资源化"、"减量化"的有效措施处理飞灰,即水泥窑煅烧处理;还介绍了城市垃圾焚烧产物中二噁英的基本性质、毒性和对人体的危害,从垃圾入炉前、焚烧时、烟气中等三个方面进行处理,并提出了减少二噁英的生成防治措施及去除的方法;介绍了城市垃圾焚烧底灰的物理化学性质,提出了一种资源化利用的方案,即制成烧结砖.     

The fate of chlorine during MSW incineration: Vaporization,transformation, deposition,corrosion and remedies

Municipal solid waste (MSW) incineration plays an important role in waste treatment systems throughout the world, due to the advantages of fast volume reduction by 80–90%, heat recovery, and power generation. However, waste-to-energy (WtE) plants have low electrical efficiency of 15–25%, due to the low steam temperature and pressure used in order to minimize boiler deposition and corrosion problems. Undoubtedly, the high Cl-content in MSW is the reason for the severe corrosion problem. Chlorine also forms volatile compounds with trace metals (e.g., Zn, Pb), and, influences the fate of other key elements, e.g., Na, K, and S.Different from alkali metals in biomass, which have been thoroughly investigated, the behavior of chlorine during MSW incineration has not been systematically and comprehensively studied. Up until now, there are few in-depth studies that have been conducted on the thermal behavior of chlorine or on the remedial measures against Cl-induced problems. An up-to-date review on the behavior of chlorine from incineration via freeboard chemistry to corrosive attack is therefore needed, in order to provide knowledge on process optimization and reactor design, thereby enabling high-efficient energy utilization and safe operation of large-scale WtE units.This review provides a critical summary of the progress of research on chlorine in MSW (origins, species, and analytical methods); the thermal behavior of chlorine, including chlorine vaporization, aerosol formation and transformation (freeboard chemistry), deposit formation, and Cl-initiated corrosion mechanisms. In addition, the interrelationship of chlorine with other key elements (S, Na, K, Zn, Pb), and, the chlorine roadmap in the incineration process is presented, along with the influence of feedstock composition and the temperature of both the flue gas and boiler tube metal on chlorine-induced deposition and corrosion.Mitigation measures against Cl-initiated problems such as Segher boiler prisms, mixed secondary air injection, and eco-tube systems, are also thoroughly discussed. Finally, challenges and further research questions, are identified.     

Emission reductions potential for energy from municipal solid waste incineration in Chongqing

Municipal solid waste (MSW) is a potential energy resource which can be incineration to energy. Furthermore, it can conserve more valuable fossil fuel and improve the environment by lessening Greenhouse Gas (GHG) emission and the amount of waste that must be landfilled. This paper highlights the MSW generation and characteristics for the city of Chongqing, the nation's fourth largest municipality after Beijing, Shanghai and Tianjin. At present the daily amount of MSW generated per person is about 0.85 kg; food waste accounts for about 53.7% of total MSW. MSW in Chongqing has higher moisture content and lower net caloric value, which is an obstruction for incineration. This paper examines the emission reductions potential for MSW incineration power plant in urban Chongqing. As a case study, emission reductions analysis and economic assessment was implemented for Tongxing MSW incineration power plant. The results show that with the power displacement potential at 235 060 MWh, Chongqing is expected to generate emission reductions as much as 815 862–827 969 tCO₂ and net profit US$7.72 million per annum.     

生活垃圾焚烧电站烟气净化技术的应用

阐述目前我国生活垃圾的特点,提出生活垃圾焚烧的必要性,简述生活垃圾焚烧过程中所产生的烟气污染成分。根据国家对垃圾焚烧电站烟气处理的要求和排放标准,提出现阶段国内外较常运用的三种生活垃圾电站的烟气净化技术工艺,并对比其优缺点。总结出目前最受国内外欢迎的垃圾电站烟气净化技术工艺特点和应用实例,归纳出半干法烟气净化技术净化效率较高、投资和运行费用低、流程简单等优点,是一种极具发展前途的生活垃圾焚烧电站烟气净化技术工艺。     

垃圾焚烧的二次污染物排放处理

随着垃圾焚烧技术的不断发展,由此产生的二次污染问题也日益显现出来,主要包括垃圾焚烧所产生的飞灰污染、烟气中二恶英以及重金属的污染,特别是二恶英污染已引起全世界的关注,这对垃圾焚烧工艺的进一步发展提出了新的挑战。污染给人类的生存环境造成了很大的破坏,严重威胁着人类的安全。因而,二次污染物的排放控制问题成为亟待解决的问题。本文就垃圾焚烧所产生的二次污染物的排放处理进行讨论。     

化工有机废液流化床焚烧处理的结焦结渣问题研究

化工有机废液流化床焚烧过程中,碱金属盐类在炉膛受热面沉积,造成炉膛的结焦结渣:熔融的碱金属盐类沿炉壁流到床层,在床温条件下形成低熔点共晶体,引起床料的粘结、破坏流化,最终导致床层严重结焦结渣。论述了有机废液流化床焚烧炉结焦结渣的形成机理、影响因索及其抑制措施。     

垃圾综合治理焚烧过程中重金属的迁移规律

对实际运行中的垃圾焚烧炉灰渣的重金属含量和分布等物理特性进行测试分析，对各种元素间重金属分布特性的相关性及重金属迁移对运行设备造成的影响进行了详细的探讨，为灰渣填埋的重金属控制和化学稳定性措施与灰渣材料化治理利用提供基础。     

Energy potential from municipal solid waste in Malaysia

The average amount of municipal solid waste (MSW) generated in Malaysia is 0.5–0.8 kg/person/day and has increased to 1.7 kg/person/day in major cities. This paper highlights the MSW characteristics for the city of Kuala Lumpur. Currently, the waste management approach being employed is landfill, but due to rapid development and lack of space for new landfills, big cities in Malaysia are switching to incineration. A simple evaluation was conducted to establish the amount of energy that would be recovered based on the characteristics of the MSW if it were to be incinerated. From the characterization exercise, the main components of the Malaysian MSW were found to be food, paper and plastic, which made up almost 80% of the waste by weight. The average moisture content of the MSW was about 55%, making incineration a challenging task. The calorific value of the Malaysian MSW ranged between 1500 and 2600 kcal/kg. However, the energy potential from an incineration plant operating based on 1500 ton of MSW/day with an average calorific value of 2200 kcal/kg is assessed to be at 640 kW/day.     

城市生活垃圾焚烧飞灰中重金属污染与控制

针对城市生活垃圾焚烧飞灰中的重金属污染问题,介绍了焚烧飞灰中重金属生成机理及来源,并重点阐述了国内外对焚烧飞灰中重金属的稳定化处理方法及控制措施,为垃圾焚烧飞灰的无害化、资源化处理提供了必要的理论参考,并提出了未来垃圾焚烧飞灰中重金属污染物处理的发展方向.     

浅议山西省城市生活垃圾焚烧发电

通过对山西省城市生活垃圾焚烧发电的调研,介绍了山西省垃圾焚烧发电的现状以及基本工艺流程。指出山西省城市生活垃圾焚烧发电中存在的问题,并对相应的问题提出了解决办法。